A airbearing device is mainly applied to ultra-precision machining equipment, playing a role of supporting precise moving components. Relative to the traditional mechanical contact guide rail support, there is no direct contact between a airborn moving component and a support member, which avoids contact friction in a moving process, and the moving precision can be improved greatly; therefore, the airbearing device has been widely used in fields of ultra-precision machining, electronics manufacturing, precision measurement, zero-gravity simulation and the like.
A basic form of the airbearing device is as follows: after passing through a pore or slit throttling device, compressed air flows into a gap between a moving component and a support component, to form a high pressure gas film, which provides certain supporting force for the moving component. When the gap (that is, the thickness of the gas film) between the moving component and the support component decreases, the pressure of the gas film increases, the bearing capacity of the airbearing increases and the airbearing has certain stiffness. That is to say, bearing capacity and stiffness of the airbearing device form one of the key factors for the airbearing device to function in various applications.
Various method of improving the bearing capacity and the stiffness of the airbearing device have been proposed in the prior art, for example, improvements are made to structural shapes, dimensions and other aspects of an orifice and a pressure cavity of airbearing, but improvements to the bearing capacity and the stiffness of such a airbearing device in unit area, which thus restricts its applications in ultra-precision machining or high speed spindle relative to heavy load; in addition, in the prior art, active airbearing is also proposed which uses an actuating element to adjust an open section area of the orifice or the length of the orifice, but such a solution merely has a better effect of adjusting damping characteristics of the airbearing, which is still limited in the effect of adjusting supporting force and stiffness.